At present, with the continuous development of the display technology, the virtual reality (VR) technology and the near eye display (NED) technology have attracted more and more attention from people. The near eye display technology is a technology which can project an image directly into a viewer's eyes, so as to realize an immersive display experience.
Usually, a screen of a near eye display device is within ten centimeters of an eyeball, the image on the screen is too near to be seen by human eyes. Therefore, the near eye display device needs to focus an image through a lens and project the image on human retina, and the image is processed through a visual nervous system, and then an enlarged virtual image appears in front of a user. Thus, the near eye display device can be used in the virtual reality technology or the near eye display technology.